1. Field of the Invention
This invention relates to inorganic synthesis techniques and more particularly to the inorganic synthesis of energetic oxidizer salts.
2. Description of the Related Art
Hydroxylamine nitrate (HAN) has been produced commercially by electrochemical treatment of nitric acid, by aqueous ion displacement, and by ion exchange. When using any of these synthesis methods, the product is an aqueous solution of HAN. A time and energy consuming vacuum evaporation of water technique is necessary to extract solid HAN from the solution. The water from such an aqueous solution of HAN becomes more difficult to remove as the HAN concentration increases. This requires ever increasing vacuum and temperature conditions to complete the extraction process. These operating conditions make a processing plant vulnerable to an accident; the loss of vacuum or an air leak would result in air mixing with the hot HAN solution, causing a fume-off and possibly a detonation. Addition of an alcohol or other solvent which forms a water azeotrope can improve the water removal and reduce the danger of an accident. However, the process remains difficult, expensive, and dangerous.
Other HAN production techniques involve the reaction of hydroxylamine sulfate with various reagents to produce an aqueous or an alcoholic solution of hydroxylamine which is then neutralized with nitric acid to produce a solution of HAN. Examples of these methods are found in U.S. Pat. Nos. 4,954,328 and 4,956,168. As with the method above, these processes produce solutions of HAN and not HAN salt. Hazardous, energy expensive processes of distillation or evaporation are still required to isolate the salt from solution.
Therefore, it would be desirable to provide a simpler, safer, less expensive method of producing HAN salt.